A Patient Presents With Maculopapular Rash Of Penicillin Allergy

A 22 Year old patient presents with community acquired pneumonia and was reported to have allergy to penicillin. How would you approach this patient?

Clinical Approach To  Case Of Penicillin Allergy:

History Of Presenting Complaints:


1. Always make clear what the patient actually means by 'allergy'. A large proportion of patients are unable to give any further information. Some may give a vague statement like .... my mother told that I was allergic..... or some may report side effects of drugs that are not related to allergic phenomenon. e.g nausea, diarrhoea, headache etc.

2. The most important history to get is of anaphylaxis like sever skin disorders or any other life threatening reactions.

Penicillin Allergy: The most common antibiotic allergy, reported to occur in 7-40/1000 penicillin treatment courses. Anaphylaxis occurs in 1/32 000-100 000 treatment courses.

Risk Factors For Beta Lactum Allergy: includes:

• Prior History of reaction to penicillin/beta -lactum drugs.
• Risk is greater with parenteral than with oral administration.
• Children and elderly people appear to have fewer reactions. 
• Atopy is not an independent risk factor.

Approach To Investigations And Management:

Investigations: Ig E mediated allergy to penicillin (severe immediate reactions) can be confirmed in some cases by skin prick testing. This may be helpful in individual cases but not as a general screening test.

Management: 

• There is usually an acceptable alternative antibiotic that could be prescribed. 
• If there is no previous history of drug intake patient should always be explained about the severe allergic reactions and to report immediately in case of allergy. 
• The First dose , particularly if given intravenously should be administered under supervision.